So I'm trying to figure out where I went wrong with my beer. I don't think it's infected, since it sounds like infected beers have a very strong sour flavor. My beer IS somewhat sour though. Not a bad taste, but not good either. It's hard for me to try and explain, I've tried using one of those flavor wheels but I still couldn't find the appropriate words. I took a bite out of some buffalo-chicken pizza, and then took a sip of the beer, and it tasted just like Newcastle Brown. So, I guess that means it has a vinegary taste?

The recipe was just not very well thought out, just a basic beer based very loosely on a "bitter". It consisted of 6lbs DME, and 2 oz hops total. I did 60 min of Oregon fuggles and 15 min of Kent Goldings. In retrospect, entirely too much malt and not much hops.

I dunno, what do you guys think? Infected? Is this what "malty" taste like?

Definitely on the warm side so some off flavors are probably to be expected. Also, 4 weeks from pitching to tasting is not a very long time either. How long was it in the fermenter and now bottles? If it could have stayed in the fermenter longer the yeast might have cleaned up some of the off flavor. If it was rushed out and went straight to bottle that will take even longer.

At the very least you probably need to give it another couple weeks at room temp to see if any of the unexpected flavors mellow.

I am no expert but have had what sounds like a similar situation. Had a keg full of brew that was not good tasting after a couple weeks in the keg - had an off-taste to it. I almost decided to dump it. But, I set it aside and forgot about it for several more weeks. Tried it again (cold) and it was like another beer took over. Actually tasted quite good. That keg got consumed happily.
Maybe put your bottles aside and try them again in about a month or two. In my case, it probably took 8 or more weeks after pitching to have a good taste.